Elements of Ecology

1. Presented by: LEANDRO
MICHAEL C. DE LOS SANTOS,
JR.

2. CHAPTER 6: Plant
Adaptations to the
Environment

3. Aquatic Plant Cells, Roots and Nutrients:
Aquatic plants are less rigid as they rely on the water column to keep
them upright. Many do not have roots and they instead absorb nutrients
through their foliage. This free-floating nature enables them to move and
populate different areas of the globe.
Aquatic Plants and Reproduction:
Some aquatic plants such as water hyacinth produce showy blossoms
that attract pollinators, making them a plant that reproduces by division
and seed. Seaweeds lack the ability to produce seeds; they instead
reproduce by fragmentation and spores.

4. Terrestrial Plant Cells, Roots and Nutrients:
Land plants have rigid cells that enable them to stand upright. Their roots are
more extensive than aquatic plants giving them a better footing; this allows
them to grow tall aiding them in finding light. The extensive nature of their
root systems helps them find the water and nutrients they need to survive.
Land plants are specially adapted to retain and store water for later use.
Prime example of this is cacti plants. The plants' nutrients can be stored in
not only their fruits but their roots as well.
Terrestrial Plants and Reproduction:
Many terrestrial plants reproduce by producing blossoms in hopes that they
will be pollinated. After pollination, the blossoms produce seeds that various
animals scatter and plant. Some land plant seeds are spread by the wind and
even in the gut of birds and mammals.
Read more: Difference Between Water Plants and Land Plants | Garden
Guides http://www.gardenguides.com/91053-difference-between-water-plants-land-plants.html#ixzz35vsl2QrN

5. Source: www.walden.com

6. According to the website of Climate & Global Dynamics, the size and shape
of leaves is an example of a compromise between leaf energy exchange,
leaf
temperature, and photosynthesis.
• Leaves growing in sunny environments are smaller and more deeply
lobed than leaves growing in shaded environments.
• Leafy plants growing in the hot, arid environment of deserts or cold artic
and alpine environments have small leaves.
• Under the assumption that leaf size is determined so as to maximize
water use efficiency, large leaves should occur in warm to hot climates
with low light conditions such as found in the understory of temperate
and tropical forests.
• Small leaves are favored in sunny environments (e.g. forest overstory)
and in cold climates.

8. Source: http://ib.berkeley.edu Source: Elements of Ecology 3rd ed. Smith

9. SUN LEAVES SHADE LEAVES
1. More and deeper
palisade layers
1. Better developed spongy
layer
2. Greater thickness 2. Thinner
3. Smaller leaf size 3. Bigger leaf size
4. More leaf lobbing 4. Less leaf lobbing
5. Thicker cuticle 5. Thinner cuticle
6. More hairs 6. Less hairs
7. More stomates 7. Less stomates
Source: http://ib.berkeley.edu

10. Shade Tolerance is the central paradigm for understanding forest
succession and dynamics. (Poorter, L.- National Center for Biotechnology
Information)
• Shade is thus considered a stress or disturbance to plants.
• The response of plants to stress disturbance such as shade
greatly affects their life histories. Plants growing in deciduous
forest can be categorized as Early and Late Succession
species
EARLY SUCCESSION SPECIES- are ones that colonize recently
disturbed environments. They are exposed to full sunlight and to extremes in humidity,
temperature, and wind. Seeds of early successional plants require light for
germination & can lie dormant for many years in soil, waiting for a disturbance that
opens the canopy. They are also considered shade intolerant.
LATE SUCCESSION SPECIES- germinate under a forest canopy and are
exposed to less sunlight and less variable microclimates. Seeds of late successional
plants do not require full sunlight for germination and lose viability rapidly. They are
also considered shade tolerant.
Source: http://www.cgd.ucar.edu

11. Source: http://www.cgd.ucar.edu
In a study conducted by Poorter, L. from National Center for Biotechnology
Information, shade tolerance was also compared between tropical moist
semi-evergreen forest (1580 mm rain yr(-1)) and 41 species from a dry
deciduous forest (1160 mm yr(-1)) in Bolivia. The result of the study was
shade adaptations of plants vary with climatic control. In the moist evergreen
forest leaf traits underlying the growth-survival trade-off are important (as
shade adaptations exclusively found in the evergreen moist forest were
related to tough & persistent leaves) , whereas in the seasonally deciduous
forest leaf traits underlying the growth trade-off between low and high light
might become important (shade adaptations were related to high light
interception and water use).

12. Yes. The two groups share common characteristics
because of “convergence adaptations”. These desert
plants have converged on succulent features as an
adaptation to life in an arid environment.
Source: http://www.mapoflife.org (University of
Cambridge)
The following diagram (or
phylogeny) shows the
relationships between these
stem and leaf succulent
groups, highlighting their
evolutionary separation and the
fact that shared features have
arisen by independent
innovation.

13. Source: http://www.mapoflife.org (University of
Cambridge)
Fleshy, succulent stems have evolved in several distantly related desert plant
families, including cacti (family Cactaceae), certain species
ofEuphorbia (Euphorbiaceae) and two genera of the family
Asclepiadaceae, Hoodia and Stapelia. Shared features of all these plants
include a succulent stem adapted for water storage and photosynthesis,
protective spines, highly reduced or absent leaves and a photosynthetic
mechanism termed 'Crassulacean Acid Metabolism',
or CAM photosynthesis which conserves water in a process that entails the
opening of stomata and fixing of CO2 almost exclusively at
night. CAM photosynthesis is itself convergent, having evolved
independently many times in plants and even certain algae.
Opuntia cactus Euphorbia

14. Source: http://www.mapoflife.org (University of
Cambridge)
Perhaps the most striking case of convergence among leaf succulents
occurs between Agave (Agavaceae) and its relatives Yucca and
Hesperaloe in the Americas and Aloe (Asphodelaceae) and its relatives
(e.g. Haworthia and Gasteria) in Africa. All of these plants have a generally
similar form of succulent leaf rosette and have evolved CAM photosynthesis
(itself convergent), a process that entails the opening of their stomata and
subsequent fixing of CO2 only at night when the air is cooler and holds less
water.
Blue agave Aloe dichotoma

15. Source: http://http://www.bgci.org
Effects on Plant Diversity:
1. Plant genetic composition may change in response to the selection
pressure of climate change.
2. Some plant communities or species associations may be lost as
species move or adapt at different rates.
3. Increased invasions by alien species may occur, as conditions
become more suitable for exotic species whilst native species
become less well suited to their environment (for
example, Bromus is more invasive in wet years (Smith et al, 2000)).
This is especially true given human interventions which have
deliberately and accidentally facilitated the spread of species across
the globe.
4. Many plant communities act as 'sinks' (store carbon), which helps to
offset carbon emissions. However, over the next 70 years, the
effects of climate change on plants mean many terrestrial sinks
may become sources.

16. • Animals, plants and even insects are now adapting quickly to shifts in
temperatures, often by migrating to cooler climates, modifying their diets
and altering breeding cycles.
The Comma butterfly, for example, has migrated north from central
England to Edinburgh, Scotland – a distance of more than 130 miles –
over the past 40 years. They found that the Cetti warbler, a small bird, has
moved more than 90 miles north.
Changes are also evident in breeding cycles. New storm patterns brought
on by climate change have affected when tropical tree frogs lay their eggs,
the Smithsonian Tropical Research Institute has found.
These samples of adaptations can possibly be in conflict with a different
environmental problem such as species invasion of a new territory for
example the Comma butterfly.
Source: Reuters

17. Bluebells - under threat from warmer
springs
The Quiver Tree - threatened by encroaching
desert
Source: http://www.bgci.org
Coco de Mer Platanthera leucophaea

18. Source: http://www.pnas.org
Global climate change has already had observable effects on the
environment. Glaciers have shrunk, ice on rivers and lakes is breaking
up earlier, plant and animal ranges have shifted and trees are flowering
sooner.
Effects that scientists had predicted in the past would result from global
climate change are now occurring: loss of sea ice, accelerated sea level
rise and longer, more intense heat waves (http://climate.nasa.gov/effects)
The tested
hypotheses
regarding the
impact of warming
on body size at
different biological
scales

19. CHAPTER 7: Animal
Adaptations to the
Environment

20. • Implications of these differences mean that plants and animals have certain roles and functionalities in the
whole biosphere. Though these two organisms have their specific roles in any given ecosystem, it is useful to
focus on these differences as they also exhibit certain relationships that are interdependent with one another.
“The mutually beneficial interactions between plants and their animal pollinators and seed dispersers have been
paramount in the generation of Earth's biodiversity. These mutualistic interactions often involve dozens or even
hundreds of species that form complex networks of interdependences. ”- J. Bascompte & P. Jordano
• It is useful to seek commonalities among plants and animals when we study about their evolutionary traits in
relation to their common locations and also when studying about their recent adaptations to global changes. In
studying these, we may know if plants and animals are mutating in somewhat similar manner and if they are
also adapting to recent changes in similar manner also.

21. Human health is directly linked to, and correlated with, a healthy,
diverse ecosystem. For example, when coral reefs die, fish die.
About 75 percent of the world’s fish catch is used for human
consumption. No fish, no food.
We use the natural ecosystem for food, fresh water, medicines,
clothing and much more. A report for the 2013 National Climate
Assessment concluded that the extensive changes in these
ecosystems will have important implications for future human activity,
including what we eat and how we live.

22. Human health is directly linked to, and correlated with, a healthy,
diverse ecosystem. For example, when coral reefs die, fish die.
About 75 percent of the world’s fish catch is used for human
consumption. No fish, no food.
We use the natural ecosystem for food, fresh water, medicines,
clothing and much more. A report for the 2013 National Climate
Assessment concluded that the extensive changes in these
ecosystems will have important implications for future human activity,
including what we eat and how we live.

23. Ectotherms - obtain most of their heat from outside their body
Endotherms - generate most of their heat internally
Poikilotherms - allow their body temperature to vary widely.
Homeotherms - keep their body temperatures within a limited range.
Evidence for dinosaur thermoregulation strategies:
1. Were they warm or cold?
2. Were they homeotherms (invariant temperature) or heterotherms
(variable temperature)?
3. Did they have high metabolic rate or low metabolic rate?

25. Bottom line:
Dino babies were warm. Since they had no inertial heating, they had high
metabolic.
Small theropod dinosaurs were probably warm. Since they had no inertial
heating, they may have had high metabolic rate, but low nasal volume is
troubling.
Large theropods were warm. Inertial homeotherms or high metabolism.
Large dinosaurs had to be warm, but with relatively low metabolic rates. 4
As they grew from babies to adulthood, they slowed down their metabolic
rate.
Reconstruction of dinos as warm and active is correct, but many dinosaurs
didn’t achieve this state in the same way as mammals or birds.
Source: http://www.es.ucsc.edu

26. Hypothermia Avoidance-
Some animals are faced with trade-offs to avoid hypothermia during cold
exposure. This is the trade-off between acquiring and conserving energy.
The increase in ingested food is the way to increase energy availability, while
nest-sharing and basking behaviours are the most useful to save energy- J.
Terrien , M. Perret, F. Aujard- Behavioural thermoregulation in mammals: A
review.
Animals introduced to this kind of trade-off have to choose one over the other
so as to ensure survival during extreme weather condition.

27. DIURNAL RHYTHM- a circadian rhythm that is synchronized with the
day/night cycle
¹ Circadian rhythms are physiological and behavioural rhythms and include:
– sleep/wakefulness cycle
– body temperature
– patterns of hormone secretion
– blood pressure
– digestive secretions
– levels of alertness
– reaction times
(Source: http://ergo.human.cornell.edu)
Alterations of circadian rhythms have been associated with several disease
states. Several epidemiological studies have demonstrated an increased
incidence of metabolic syndrome among night shift workers who have
chronically disrupted circadian rhythms. Supporting evidence comes from
CLOCK mutant mice, shown to be hyperphagic and obese and to develop

28. Shift Work:
20% US workforce (22 million workers) work outside of normal Mon.-Fri. 9-
5pm workday (Shiftwork Practices, 1999).
“Industrial jet lag" -- fatigue that results when the body hasn’t adjusted its
circadian rhythms to temporal shift changes.
After three or four night shifts, the body still won’t be 100% adjusted to night
work, but circadian rhythms will have shifted enough to make it easier to stay
alert throughout the night.
Circadian rhythms can only shift an hour or two per day when a person
changes his or her sleep schedule, so resynchronization (entrainment) takes
time.
(Source: http://ergo.human.cornell.edu)